JPH0582280B2 - - Google Patents

Description

[Detailed description of the invention]

a. Industrial Application Fields The present invention is capable of treating excavated soil generated during excavation for petroleum, natural gas, geothermal energy, or civil engineering work, as well as sludge such as soft earth and sludge generated during civil engineering work or dredging work. The present invention relates to a method for processing sludge into a form that can be easily reused or disposed of. b. Prior Art In general, sludge generated during excavation, dredging, etc. for oil, natural gas, geothermal energy, or civil engineering works has a moisture content of about 20 to 90%, although it varies depending on the region. Conventionally, these sludges containing a large amount of water are squeezed until the water content is 45 to 50% or less, and then
It was treated by mixing cement-based solidifying agents. c Problems to be Solved by the Invention However, in the method of treating sludge using only a cement-based solidifying agent, the sludge loses its fluidity after treatment, and it takes a long time for the sludge to reach a strength suitable for disposal. (Specifically, it takes 24 to 72 hours). It also has the disadvantage of high pH. That is, in order to give solidified sludge a certain level of strength suitable for disposal, it is necessary to add a large amount of cement solidifying agent (specifically 10 to 15% by weight). However, if more than 10% by weight of this solidifying agent is added, the pH of the sludge will rise to 12 or higher during the solidifying process, making it necessary to adjust the pH. However, it has been pointed out that the drawback is that it is very difficult to adjust the pH. The present invention aims to solve these problems, and its purpose is to efficiently solidify sludge,
The object of the present invention is to provide a processing method for reusing or disposing of containers. d Means for Solving the Problems The gist of the present invention is that excavated soil generated during excavation,
and at least one type of sludge selected from the group consisting of soft earth and sand and sludge generated during civil engineering work and dredging work, etc. When treating sludge by adding and mixing at least one polymeric substance, first measure the water content of the sludge, and if the measured water content is 20% or more and 50%
If the water content is less than 0.5Kg or more and 8Kg or less per 1Kl of sludge, and if the water content is 50% or more and 80% or less, add more than 8Kg but not more than 25Kg of the above polymer substance per 1KL of sludge. ,
A sludge treatment method characterized by solidifying the sludge. The sludge treated by the method of the present invention is at least one type selected from the group consisting of excavated soil generated during excavation, and soft earth and sand and sludge generated during civil engineering work and dredging work. These sludges contain a large amount of water. In other words, the sludge of the present invention contains a large amount of water (usually a water content of 20 to 80%), and is difficult to treat by conventional processing methods that use cement-based solidifying agents. The polymeric substance used in the treatment method of the present invention is at least one selected from the group consisting of natural water-soluble polymeric substances and semi-synthetic polymeric substances thereof. The above-mentioned natural water-soluble polymer substances include plant-based seed polysaccharides such as guar gum, locust Bingham, quinseed gum, and tara gum; resin polysaccharides such as arabinogalactan gum, gum arabic, gum tragacanth, and gum karaya; carrageenan, alginic acid, and furcelan. , seaweed polysaccharides such as agar;
Fruit polysaccharides such as pectin and psyllium gum;
Examples include rhizome polysaccharides such as starch, konjac, and mallow; microbial products such as xanthan gum, xancort, xanfuro, curdlan, and succinoglucan; and animal products such as gelatin, casein, albumin, and succinoglucan. In addition, the semi-synthetic polymer substances include starch,
Precipitated derivatives obtained by treating guar gum, roasted bean gum, cellulose, etc. with oxidation, methylation, carboxymethylation, hydroxyethylation, hydroxypropylation, phosphorylation, cationization, etc.; Guarcam derivative; roasted bean Gum derivative; a cellulose derivative,
Examples include methylcellulose, carboxymethylcellulose, carboxymethylhydroxyethylcellulose, and hydroxypropylcellulose. Furthermore, alginic acid salts as alginic acid derivatives, alginic acid propylene glycol ester, etc. are also included in the semi-synthetic polymeric substances of the present invention. Note that natural water-soluble polymeric substances similar to these and semi-synthetic polymeric substances thereof can also be used in the present invention. Water-soluble,
Materials that utilize thickening properties, water absorption properties, or aggregate properties, such as inorganic substances such as bean gum and bentonite, can be effectively used in the present invention together with the polymeric substances of the present invention. All of these polymeric substances are highly hydrophilic, and these polymeric substances themselves have characteristics such as water solubility, thickening properties, water absorbing properties, and agglomerating properties. The present invention takes advantage of its adhesive effect, water absorption effect, collection effect, etc. to thicken sludge, collect it, dehydrate it, etc., and convert the sludge into a powder with a size suitable for disposal. It is made into a form that can be reused or disposed of. In the present invention, when the above-mentioned polymeric substances are added and mixed into sludge with a high moisture content, these polymeric substances are physically or chemically adsorbed on the particle surface of the sludge,
At the same time, it neutralizes the electric charge on the particle surface and changes the entire sludge into a coagulated and coagulated state. Alternatively, the polymer substance itself has
It absorbs the water contained in sludge due to its water-solubility and water-absorbing properties, converting the sludge into a powder-like solid with less stickiness, making it easier to reuse or dispose of. In the method of the present invention, in order to achieve the agglomeration and coagulation state more effectively and quickly by adding the above-mentioned polymeric substance, or to obtain a state with higher strength, divalent or higher cations are added. It is also effective to add the compound separately or simultaneously with the above-mentioned polymeric substance. In the present invention, the range of the amount of these polymeric substances added varies depending on the type of sludge, the water content of the sludge, etc., but is particularly closely related to the water content. Therefore, in the present invention, the moisture content of the sludge is measured in advance using an ultraviolet moisture measuring device, and the amount of the polymeric substance of the present invention to be added is determined based on the measured value. In other words, if the measured moisture content is 20% or more and less than 50%, the polymeric substance of the present invention should be added per 1Kl of sludge.
If the weight is 0.5 kg or more and 8 kg or less, and the water content is 50% or more and 80% or less, 8 kg of the polymeric substance of the present invention is added per 1 Kl of sludge.
Add more than Kg but not more than 25Kg. Note that when the water content of the sludge exceeds 80%, the amount of the polymeric substance used in the present invention increases rapidly. The moisture content of sludge that can be treated by the method of the present invention is
The moisture content is 20-80%, but those with a moisture content of 20-50% can be effectively treated. e Examples Hereinafter, the present invention will be described in more detail with reference to Examples. In addition, in the following examples and comparative examples,
Unless otherwise specified, % means % by weight. [Example 1] Sandy silt (specific gravity
1.60; water content 33.3%) Carboxymethylcellulose was added to 1Kl and kneaded, followed by a penetration test. As a comparative example, slaked lime or Portland cement was added and mixed, and then a penetration test was conducted. The results are shown in Table-1.

[Example 2]

Silty excavated soil (specific gravity) generated during civil engineering work
Sodium alginate was added to 1Kl (1.53; moisture content 62%), mixed, and then a penetration test was conducted. The results are shown in Table-2.

[Example 3]

Guar gum was added to 1Kl of soft earth and sand (specific gravity 1.75; moisture content 29.3%, silt and clay content 65.3%) generated during civil engineering work, mixed, and then a penetration test was conducted. As a result, guar gum was added to 1Kl of soil and sand.
It has been found that earth and sand can be preferably solidified by adding 0.029 to 0.46% by weight, preferably 0.40 to 0.46% by weight. The pH of the treated products in Examples 1 and 2 above was measured. The results are shown in Table-4.

[Comparative example 3]

Sandy silt was treated in the same manner as in Example 1, except that water-soluble sodium polyacrylate was used instead of carboxymethyl cellulose. Table 5 shows the results of the penetration test and the pH of the treated material. [Comparative Example 4] Sandy silt was treated in the same manner as in Example 1, except that Sumikagel (water-absorbing resin) was used instead of carboxymethylcellulose. Table 5 shows the results of the penetration test and the pH of the treated material.

[Table] f Effects of the invention According to the method of the invention, excavated soil generated during excavation, soft earth and sand generated from civil engineering work, dredging work, etc., and sludge such as sludge can be efficiently treated and reused or disposed of. It can be made into an easy form. Furthermore, in the method of the present invention, the water content of the sludge is measured in advance and an appropriate amount of the polymeric substance is used, so that the polymeric substance of the present invention can be effectively utilized. The polymeric substance used in the present invention can also be used as a circulating fluid for drilling by appropriately adjusting the viscosity as an aqueous solution or suspension.

Claims (1)

[Claims] 1 At least one type of sludge selected from the group consisting of excavated soil generated during excavation, and soft earth and sand and sludge generated during civil engineering work and dredging work, is mixed with natural water-soluble polymer substances and semi-natural water-soluble polymer substances. When treating sludge by adding and mixing at least one polymeric substance selected from the group consisting of synthetic polymeric substances, first measure the moisture content of the sludge, and if the measured moisture content is 20%. If the moisture content is 50% or more and less than 50%, add 0.5kg or more to 8kg or less of the above polymeric substance per 1Kl of sludge, and if the water content is 50% or more and 80% or less, use more than 8kg of the polymeric substance per 1Kl of sludge.
A sludge treatment method characterized by solidifying the sludge by adding and mixing 25 kg or less.